Piping Connection - Haier HBU-18CF03 Service Manual

Precautions for refrigerant piping
Do not twist or crush piping.
Be sure that no dust is mixed in piping.
Bend piping with as wide angle as possible.
Keep insulating both gas and liquid piping.
Check flare-connected area for gas leakage.

Piping connection

Connecting method (indoor unit)
Apply refrigerant oil at half union as large and flare nut.
To bend a pipe, give the roundness as possible not to crush
the pipe.
When connecting pipe, hold the pipe centre to centre then
screw nut on by hand, refer to Fig.
Be careful not to let foreign matters, such as sands enter
the pipe.
Forced fastening without centering
may damage the threads and cause
a gas leakage.
Air discharging method
After finishing connection of refrigerant pipe, it shall perform air tightness test.
The air tightness test adopts nitrogen tank to give pressure according to the pipe connection
mode as the following figure shown.
The gas and liquid valve are all in close state. In order to prevent the nitrogen entering the
circulation system of outdoor unit, tighten the valve rod before giving pressure (both gas
and liquid valve rods).
Indoor
Completely tightened
Completely tightened
Indoor units
19
Commercial Air Conditioner
3-way valve totally closed
(Gas side)
Outdoor
Flare part
Flare part
2-way valve totally closed
(Liquid side)
Model: HBU-18CF03
HDU-42CF03/H HPU-42HF03
Pipe diameter
Liquid pipe 6.35mm
Liquid pipe 9.52mm
Gas pipe 12.7mm
Gas pipe 15.88mm
Gas pipe 19.05mm
Low pressure gauge
High pressure gauge
VLVH
Discharging valve
Dropping valve
Mainhole
Outdoor units
Fastening torque
14.2-17.2N . m
32.7-39.9N . m
49.5-60.3N . m
61.8-75.4N . m
97.2-118.6N . m
Meter separator
Nitrogen tank